MONITORING OF AIR-POLLUTANTS AT KOSAN, CHEJU-ISLAND, KOREA, DURING MARCH-APRIL 1994

Gaseous species and total suspended particles were measured at Kosan, Cheju Island, Korea, between 11 March and 19 April 1994. The concentra tions of nonsea salt (nss) ions were higher than those measured in cle an marine areas of Japan and other background marine areas of the worl d, in particular, the nss sulfate concentration was comparable to that measured in Seoul. The average SO2 and NO4 concentrations were approx imately 0.97 and 3.5 ppb, respectively, which were lower than those at other urban areas in Korea but higher than those of other remote area s in the world. in contrast, the average O-3 concentration was approxi mately 55 ppb, which is comparable to or higher than those at remote s ites in Japan that were influenced by long-range transport of air poll utants. Half of the air parcels during the period were from northern C hina and about 30% of the air parcels from southern China. The main di fference of air pollutant levels between the two areas was higher crus tal species and lower nss sulfate concentrations for air parcels from northern China. The nss SO42- concentrations had a strong correlation with nss K+, NH4+, and O-3 concentrations. In addition, the nss Ca2+ c oncentrations had a strong correlation with the nss K+ and nss Mg2+ co ncentrations. It was suggested that nss K+ had two sources: anthropoge nic and crustal.